Study Evaluating the Efficacy and Safety of Selinexor (KPT-330) in Participants With Recurrent Gliomas

Inclusion Criteria:

* Pathologically confirmed GBM (including all histologic variants) at first diagnosis with radiographic evidence of recurrent disease after treatment with radiotherapy and temozolomide;
* 18 years of age or older
* Participants enrolling in the medical arm (Arms B, C and D) must be on a stable or decreasing dose of corticosteroids (or none) for at least 5 days prior to the baseline MRI;
* Measurable disease (according to RANO guidelines)
* Surgical arm (Arm A) must be predicted pre-operatively to have sufficiently sized tumor to be resected and provide tissue samples for exploratory assessments.

Exclusion Criteria:

* Markedly decreased visual acuity if attributed to other causes than GBM.
* Known active hepatitis A, B, or C
* Participants with coagulation problems and medically significant bleeding in the month prior to start of treatment (e.g., peptic ulcer, epistaxis, spontaneous bleeding). Prior history of DVT or PE is not exclusionary.
* Participants must not have significantly diseased or obstructed gastrointestinal tract, malabsorption, uncontrolled vomiting or diarrhea, or inability to swallow oral medications.
* Prior treatment with bevacizumab or other direct VEGF/ VEGFR inhibitors. For any question of the definition of a direct VEGF/VEGFR inhibitor, consult Sponsor.
* Arms C and D only: body surface area \< 1.2 m².
* \< 24 days from prior temozolomide, \< 6 weeks from nitrosourea, \< 4 weeks from other chemotherapy or investigational agents prior to start of treatment within study.